Food allergy in children is a disease of growing importance, current estimation in school age children are between 4 and 8 %. The most frequently involved foods in IgE reaction in school-aged children are hazelnut (especially in Switzerland according to the ongoing Swiss Registry, Wiesner et al, personal communication) and peanut. Tree nuts and peanut allergies are often involved in severe reactions, including cases of death by anaphylaxis. In addition, the disease is long-lasting as Fleischer et al could show that only 9% of children with nut allergies will outgrew from it. This number is worse than for peanut where a positive outcome is seen in 20% of the patients.